<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>更新时的问题</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
  </head>
  <body>
    <div id="root">
      <h2>人员列表</h2>
      <button @click="update" >更新马冬梅的信息</button>
      <ul>
        <li v-for="person in persons" :key="person.id">
          {{person.name}}-{{person.age}}-{{person.sex}}
        </li>
      </ul>
    </div>

    <script>
      const vm = new Vue({
        el: "#root",
        data: {
         persons: [
            { id: "001", name: "马冬梅", age: 18, sex: "女" },
            { id: "002", name: "周冬雨", age: 20, sex: "女" },
            { id: "003", name: "周杰伦", age: 21, sex: "男" },
            { id: "004", name: "温兆伦", age: 23, sex: "男" },
          ]
        },
        methods: {
            update() {
                // this.persons[0].name = '马老师'//奏效
                // this.persons[0].age = 50//奏效
                // this.persons[0].sex = '男'//奏效
                // this.persons[0] = {id: "001", name: "马老师", age: 50, sex: "男"} //不奏效
                this.persons.splice(0, 1, {id: "001", name: "马老师", age: 50, sex: "男"})
            }
        }
      })
    </script>
  </body>
</html>
